Regarding their selection in the encyclopaedia we followed three criteria:

- Their integration in the wider Hellenic cultural group, which is delimited according to the historical period - The development of important action, and finally - Their local character in relation with the specific historical-geographical area.

As a wider Hellenic cultural unit we consider a group of people in synchrony, the members of which share a number of ethnic, cultural and historical characteristics, as these appear, evolve and differentiate per historical period (language, religion, political structure, etc.) Therefore, regarding antiquity, the use of the Hellenic language as well as participation in state institutions, which date back from the world of classical Greece, is of great importance. Equally important is their participation in the wider Hellenic “common” cultural tradition. Regarding the Byzantine period, the reference framework includes the persons that were active within the Byzantine Empire as well as those who generally participated in the Byzantine culture. Finally, in the modern period emphasis is given to the religious element, that is to the Christian Orthodox population and the use of Greek language.

As significant action we consider any intentional action taken by a person, within or outside the institutions and with short or long duration, the results of which have direct or indirect, short term or long term consequences for a wider social sub-group. Therefore, we do not consider that only high officials (i.e. kings, emperors, patriarchs, officials) were capable of significant actions, but also people who didn’t have an institutionally established role (insurgents, leaders of riots, scholars, artists, etc.).

Nativeness means that the person in question descends from the geographical area under examination and / or important action has been undertaken within this area or in direct relation to it. Aside from the people that meet these criteria, there are also other persons who took important action within this particular area which is in intense interaction with the Hellenic element are also included, although they do not belong to the wider Hellenic cultural group (e.g. intellectuals and artists). However, their action immediately concerns the Hellenic element (e.g. Roman emperors, Ottoman landowners and strong local families). This was deemed necessary so that a wider image of each Hellenic cultural element could be given in relation with its neighboring cultures and the wider social and political realities to which it was subject. Speaking generally, and in order to outline this part of the encyclopaedia, it can be said that the main body of the entries regarding persons includes:

Aside from the people that meet these criteria, there are also other persons who took important action within this particular area which is in intense interaction with the Hellenic element are also included, although they do not belong to the wider Hellenic cultural group (e.g. intellectuals and artists). However, their action immediately concerns the Hellenic element (e.g. Roman emperors, Ottoman landowners and strong local families). This was deemed necessary so that a wider image of each Hellenic cultural element could be given in relation with its neighbouring cultures and the wider social and political realities to which it was subject.